1. Field of the Invention
The present invention relates to a mixing apparatus for viscous emulsions, and more particularly, relates to a mixing apparatus incorporating a novel mixing chamber for the blending and homogenizing of at least one composition and/or air with a base emulsion in order to impart a specified and intended consistency and texture to a product produced from the emulsion. Furthermore, the invention is also directed to the provision of a novel method for producing the product formulated from the viscous emulsion by utilizing the inventive mixing apparatus; and to a resultant viscous flowable product of improved and specified consistency and texture, such as mayonnaise, mayonnaise-type emulsion or salad dressing through the inventive mixing apparatus and method.
In the large-scale commercial production of emulsified sauces; for instance, such as mayonnaise, mayonnaise-like products, and various types of salad dressings, it is of extreme importance not only to provide a product which is organoleptically and aesthetically appealing to a consumer, but a product which enhances its sales appeal through the affording of a specific uniformity in its consistency in appearance and texture, which renders it more palatable to a consumer.
Hereby, pursuant to the invention it is desirable to be able to impart two different kinds of viscous emulsified sauces, such as various types of mayonnaise and possibly salad dressings, with a texture which renders the final product formulated by the viscous emulsion somewhat rough in its texture or "cheesy" in body, but which seems smooth or creamy in external appearance. Although this physical application would seem to be somewhat contradictory in terms when viewed superficially, that type of texture represents a product with an enhanced aesthetic appeal to a consumer since it apparently improves upon the spreadability of the product and renders it substantial or "full-bodied" in textural appearance. Hereby, the viscous emulsion or emulsified sauce which, in the instance of a usual mayonnaise, is formulated from approximately 80% fat, generally although not necessarily soybean oil, with the inclusion of whole eggs and egg yolks, water, spices and vinegar, is generally blended and homogenized in a commercial mixer; for instance by way of example only, such as a KMF-type Pentax mixer, sold by Bran & Luebbe, Inc., Wheeling, Ill., in which there is carried out a continuous, in-line mixing of the ingredients of the viscous emulsion so as to ultimately produce a flowable viscous product of specific viscosity or consistency and/or texture. Ordinarily, the mixer has a premixing chamber connected ahead of and communicating with the inlet of the mixer, whereby a rotary blade mounted on a central shaft mixes and blends the various ingredients of the emulsion with the chamber prior to the emulsion being conveyed into the mixer itself.
Similar mixing equipment and procedures are employed for other types of emulsified sauces, such as salad dressings, light mayonnaise, cholesterol-free and cholesterol-free light dressings which, under various circumstances, in order to meet consumer demands as to their caloric and/or cholesterol contents, will eliminate whole eggs and egg yolks and substitute egg whites or albumen, reduce the proportions of oil, and replace the latter with starch bases and/or gum to meet the requirements for the reductions in cholesterol and/or calories, while still maintaining the desired consistencies or viscosities and/or textures, or organoleptic properties for the formulated product so as to render the latter attractive to a consumer.
In order to meet the demands of the industry in being able to prepare commercially large quantities of various types of viscous emulsions at high rates of output, such as different kinds of mayonnaises, mayonnaise-type emulsions, and salad dressings, of normal types as well as low-caloric and/or cholesterol-free, while using essentially the same kind of mixer, in accordance with the invention, the standard type of premixing chamber currently utilized, which receives the constituents formulating the emulsion, and which under normal circumstances employees a rotor blade providing for blending and homogenizing the constituents of the emulsion prior to introduction into the mixer, has now been replaced by a novel and unique mixing chamber at the outlet or discharge end of the mixer, which incorporates structure providing a gentle shearing or folding action to the contents conveyed therethrough when various further constituents are added to the viscous base emulsions for formulating the final product. Hereby, the mixing chamber possess a cylindrical housing having a plurality of radially inwardly extending pin members projecting into proximity with a central rotor which may be of a longitudinally ridged, splined or paddle wheel design, and in which at least one further constituent is introduced, preferably radially, into the base emulsion in the mixing chamber, wherein this base emulsion is introduced axially at an upstream or inlet end of the chamber subsequent to having been passed through the mixer, and due to the interaction of the stationary pin members and rotor, this constituent is folded in a uniform and gentle manner into the viscous base emulsions so as to blend and homogenize to formulate a product exiting from the mixing chamber which will resultingly be imparted the desired organoleptic properties, viscosity or consistency and/or texture deemed aesthetically significant to a consumer.
Hereby, the constituent or constituents which may be added to the base emulsion in the mixing chamber and folded therein to blend and homogenize therewith by means of the novel pinned chamber structure cooperating with the ridged or splined rotor, may be either a starch base when producing a viscous salad dressing or reduced-calorie mayonnaise, and/or an injection of a flow of air for the production of the normally generally 80% fat mayonnaise, thereby imparting the desired rough or "cheesy" full-bodied texture to the finished product. For various formulations of the product, in lieu of air or starch base, or in addition thereto, it may also be desirable to impart to the base emulsion vinegar or a gum as a replacement for a portion of oil and whole eggs or yolks which have been removed from the emulsion in case the latter is intended to be a formulation for an essentially cholesterol-free and/or light (low-calorie) mayonnaise or the like.
Although numerous kinds of mixers are currently known and widely employed in the technology for the blending and homogenizing of various types of viscous emulsions and similar flowable products, none of these are adapted to provide for the unique folding action to produce a blending and homogenizing between a base emulsion and an added constituent and/or air, in order to cause the thusly admixed and blended product to uniformly assume a specified viscosity or consistency and/or texture upon the discharge thereof from a mixer, so as to meet the demands of a consumer for a relatively wide range of emulsified sauces or similar products, such as mayonnaises or salad dressings, utilizing the same equipment by simply varying the types and quantities of constituents added to the base emulsion in the inventive mixing chamber.
2. Discussion of the Prior Art
Gillner, et al. U.S. Pat. No. 4,590,030 discloses a process and apparatus for producing a uniform coating or layer of film or sheet for a mixture of components, in which a mixer includes a rotor, having specific reference to FIG. 7 of Gillner, et al., providing for radially outwardly projecting blades, and interspersed therewith, a plurality of radially inwardly projecting pin members to provide for a mixing action therewith. There is no disclosure of the unique folding action provided for by a splined rotor in cooperation with radially inwardly projecting stationary pins positioned at predetermined radial and axial spacings within a mixing chamber which will cause a folding of the constituents of a base emulsion received from a mixer and other constituents added thereto so as to impart a predetermined consistency and/or texture to a product formulated therefrom.
Harms U.S. Pat. No. 4,538,917 discloses a screw-type extruder having a plurality of pins extending into the interspaces between screw flights formed on a rotor so as to provide for a shearing action on an emulsion. There is no disclosure of the unique folding action on the constituents of a viscous emulsion afforded by the inventive pinned mixing chamber.
Miner U.S. Pat. No. 4,334,788 discloses a pin action mixing pump in which a plurality of rotary and stationary pins cooperate to impart a folding and blending action to a product. There is no disclosure of the unique admixing and folding being imparted to emulsified sources in a pinned mixing chamber analogous to that of the present invention.
Wheeler U.S. Pat. No. 3,458,894 discloses a mixer in which a rotor includes a flight of screwthreads, and with pin members radially extending therebetween so as to impart a shearing and mixing action to a flowable viscous product.
Krizak U.S. Pat. No. 3,482,822 discloses a mixing device in which a plurality of radially inwardly projecting stationary pin members extend intermediate outwardly pins located on a rotor so as to impart a folding and blending action to a flowable viscous product or emulsion conveyed therebetween. However, there is no disclosure of the unique folding action and blending between a base emulsion which has been treated in a mixer with one or more further constituents in a mixing chamber connected to the discharge of the mixer and receiving the treated base emulsion therefrom at a low rate of shear so as to produce a desired consistency and/or texture in a flowable viscous emulsified product, such as a mayonnaise or salad dressing.
Sanborn U.S. Pat. No. 3,064,307 discloses a continuous-feed proportional blender wherein a rotor includes splines adapted to impart a blending or mixing action to an emulsion conveyed therepast. However, there is no disclosure of splines on a rotor cooperating with stationarily arranged radially inwardly projecting pins mounted in the housing of a mixing chamber which will enable the gentle folding in of further constituents and/or air to a viscous base emulsion so as to impart a flowable viscous emulsion or product formulated thereby with specified consistencies or viscosities and/or textures.